Sense Number 2: debase oneself, act in an undignified manner or do something that one considers below one's dignity

Examples:
I won't condescend to read others' mail.
How could she condescend to his level?
I like him because he condescends to speak to me.
He could not condescend to take any notice of their indiscretion.
How could a gentleman condescend to accept anything under three figures?